1. Field of the Invention
This invention relates to impact modification of PVC.
2. Description of the Prior Art
Although the PVC impact modifier art is a crowded one since there is a commercial need for such impact modification, it has never been suggested that ethylene oxide polymers would function as PVC impact modifiers.
Polyethylene oxide (PEO) having pendant epoxy groups, having been prepared from a monomer system comprised of an assymetrical diepoxide, i.e., one having two epoxide groups of different reactivity, has been shown to be a plasticizer for PVC, but such polymers were not shown to act as PVC impact modifiers. U.S. Pat. No. 3,297,783 to Bailey, Jr.
Branched chain alkylene oxide polymers, especially butene-1-oxide polymer, in combination with rubbery post chlorinated polyethylene has been shown to be a combined melt flow and impact modifier system for post chlorinated polyvinyl chloride (PCPVC). U.S. Pat. No. 3,453,347. However, the art of impact modification of PCPVC is quite different to that of PVC impact modification, and furthermore butene-1-oxide polymer does not in fact significantly function as an impact modifier in PVC itself.